From 0fc59d3a01820765e5f3a723733728758b0cf577 Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Mon, 2 Mar 2009 23:36:13 -0800 Subject: [PATCH] x86: fix init_memory_mapping() to handle small ranges Impact: fix failed EFI bootup in certain circumstances Ying Huang found init_memory_mapping() has problem with small ranges less than 2M when he tried to direct map the EFI runtime code out of max_low_pfn_mapped. It turns out we never considered that case and didn't check the range... Reported-by: Ying Huang Signed-off-by: Yinghai Lu Cc: Brian Maly LKML-Reference: <49ACDDED.1060508@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index e6d36b490250..b1352250096e 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -714,6 +714,8 @@ unsigned long __init_refok init_memory_mapping(unsigned long start, pos = start_pfn << PAGE_SHIFT; end_pfn = ((pos + (PMD_SIZE - 1)) >> PMD_SHIFT) << (PMD_SHIFT - PAGE_SHIFT); + if (end_pfn > (end >> PAGE_SHIFT)) + end_pfn = end >> PAGE_SHIFT; if (start_pfn < end_pfn) { nr_range = save_mr(mr, nr_range, start_pfn, end_pfn, 0); pos = end_pfn << PAGE_SHIFT;